As a long-time Canon fan, I would suggest you'd go for either SX10 or, if you want to be able to film in 720p, a SX20.
The Powershot S cameras got phenomenal zooms with IS, and beautiful video with STEREO sound. As long as you don't go over ISO 400, you're sitting pretty, otherwise you DO need to run the pix through a de-noiser. The noise is about the only thing that drags this camera series down, and about the only reason why the G series comes on top.
The Gs are great, don't get me wrong, but the Powershots S get a lot more zoom and better macro, and I like the quality of the video. Plus, to be honest, the manual controls on the S series is just as comprehensive, even if it's slightly less easy to access. Plus, as you said it yourself, you just can't beat the versatility and usefulness of an articulated screen... My DSLR aside, I don't think I'd ever go back to a "regular" fixed-screen digicam.